Cement mortar panel with prestressed biaxial reinforcement

ABSTRACT

This cement mortar panel with prestressed biaxial reinforcement is formed by a slab of cement mortar which, having a thickness ranging from 2 to 7 cms, includes a biaxial reinforcement. The slab has occluded in the cement plugs for versatile operating on the panel assembly allowing for its handling and/or fixation to a building structure via a plurality of panel fixing members. Each panel fixing member has a first end inserted in an axial blind hole of said plugs and a second opposite end which passes through a polygonal plate associated with positioning members configured to enable adjustment of a distance between the panel and the building structure. The building structure further comprises transverse sections having a portion thereof forming an upwardly open cannel-shaped cradle configured to receive one edge of the polygonal plate.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to and is acontinuation application of U.S. application Ser. No. 12/600,165, filedSep. 3, 2010, which is a national stage application filed under 35U.S.C. 371 of International Application No. PCT/ES2007/000706, filedDec. 3, 2007, which application claims further priority from SpanishApplication No. U200700993, filed May 14, 2007, and Spanish ApplicationNo. U200702060, filed Oct. 11, 1007.

BACKGROUND

1. Object of the Invention

The present invention relates, as indicated in the title thereof, to acement mortar panel with prestressed biaxial reinforcement, as well asto the manufacturing process thereof, which more precisely relates to apanel of the type prefabricated from cement mortar which, in theconstruction of buildings, is designed to close openings in thestructure of a building, both the external openings, in which case thevisible face thereof is textured to form the facade, and the internalopenings, in which case no texture is needed on its visible face, whichdelimit the internal courtyards of the building.

2. State of the Art

The present applicant is holder of patents ES 2 220 189, U.S. Pat. No.6,857,241, utility models ES 1 041 896, ES 1 045 543, ES 1 057 874 andES 1 057 875 and of patent applications EP 1 203 850 and WO0104433.

All the above mentioned patents and regional and international patentapplications disclose the process and/or means for the manufacture of alightweight panel made with cement mortar which is for closing theopenings in the structure of a building to form the external andinternal facades thereof. The panel is of reduced thickness in the rangeof 2 to 6 cms and has a prestressed biaxial reinforcement. The panel isprovided inserted in the mass thereof and extending out from the hiddenface thereof with shaped means for anchorage to the structure of thebuilding. The means preferably are formed by lengths of straight omegasection galvanized steel sections.

The said omega type section lengths inserted in the mass of the panelhave the drawback that, apart from the operation of insertion of thesaid omega shaped sections in the mortar and consequently the operationof maintaining them stable therein until the time when the mass ofmortar is sufficiently hard at the onset of setting of the mortar to beable to rely on the stability of said omega shaped lengths beingdelicate and rather laborious, the fact that said omega shaped lengthsproject out from the hidden face of the panel causes problems of spacein transportation and storage, without excluding the risk of scratchesthat may be caused in such situations on the visible faces thereof.

BRIEF SUMMARY

In order to overcome the abovementioned drawback, the solution has beenadopted of providing the panel itself with versatile operating meansallowing versatile operations to be performed therewith, either forcarrying out, in principle, handling and transportation operations of,finally, for installation and anchorage thereof in the buildingstructure.

In accordance with the above solution, there has been developed thecement mortar panel with prestressed biaxial reinforcement of thepresent invention. Accordingly, this cement mortar panel is formed by aslab of cement mortar having a thickness ranging from 2 to 7 cms andincluding a prestressed biaxial reinforcement. The reinforcement isformed by two series of prestressed cables or rods. The cables or rodsare parallel and equidistant within one same series and cross each otherorthogonally without being attached to one another to form a grid. Thecement mortar slab is provided with means for versatile operating on thepanel assembly allowing it to be handled and/or attached to thestructure of a building. The said versatile operating means are occludedin the mass of cement mortar, without extending from any of the surfacesthereof and are inserted in some of the spaces between the meshes. Atthe same time they themselves form, on one part, means for retentionthereof in the set mass of the cement mortar and, on the opposite part,anchoring means both for panel handling members and members for fixationthereof to the building structure.

One feature of the invention consists of the fact that the means forversatile operating on the cement mortar panel are embodied by plugswhich are inserted in the cement mortar mass prior to its setting andare located in the inner space of the grid formed by the biaxialreinforcement, in such a way that the retaining means thereof are housedin said cement mortar mass under the prestressed reinforcement withoutextending to the visible face of the panel, while the anchoring meansboth for panel handling members and members for the fixation thereof tothe building structure have the end portion thereof flush with thesurface of the hidden face of the panel.

One alternative to the foregoing feature is constituted by thepossibility that the means for versatile operating on the cement mortarpanel are embodied by holes made in the cement mortar mass during orafter the setting thereof and situated in the inner space of thereinforcement grid, in which appropriate versatile operating means areanchored or there are provided panel handling members and/or members forfixation to the building structure which are successively directlyinserted in said holes.

Further features of the invention related to the implementation of theversatile operating means in the form of a plug inserted in the mass ofthe panel are established by the following facts:

a—the plug forming the panel versatile operating means consists of ashort thick body having at one end the means for retaining it within theset mortar, while the rest forms the anchoring means.b—the plug forming the versatile operating means is formed by a bodymade from a material selected from the group comprising metals,synthetic and man-made plastics, ceramic materials, cement mortars andhydraulic cements.c—the retaining means provided in the plugs are formed by one or moreshoulders extending radially from an end perimetrical portion with whichthe corresponding end of the plug body is limited, preferably in form ofa flange.d—the radially extending shoulder forming the retaining means isprovided with arrangements of the group comprising slots and holes forthe passage of at least one of the reinforcements.e—the anchoring means provided in the plug are formed by a deep axialblind hole which is provided with internal reliefs and opens in a centreof a flat annular end surface which limits the correspond end of theplug body and which is flush with the hidden face of the panel, theinternal reliefs provided in said deep axial blind hole being formed byreliefs of the group comprising screw threads, bayonet fittings andbarbed surfaces.

A further feature of the invention is constituted by the fact that theanchoring means of the plug are temporally complemented by handlingmembers which are insertable, preferably threadedly, in the deep axialblind hole thereof and which, in their inserted position project beyondthe surface of the flat annular end surface limiting the correspondingend of the plug body, with a threaded end portion.

A further feature of the invention lies in the fact that the handlingmember temporally engageable in the deep axial blind hole of the pluganchoring means consists of a holding rod which is provided at one endthereof with a portion complementary to the anchoring means and which ispreferably threaded and, at the other end comprises a gripping portionwhich is complementary to an automatic gripping device which allows forhandling of the panel.

A further feature of the invention resides in the fact that the memberfor final fixation of the panel in the building structure, whileremaining operable, has one end inserted in the deep axial blind hole ofthe plug anchoring means and another end, opposite the former, forming athreaded portion which extends from the hidden face of the panel andpasses through a polygonal plate. This plate forms, on one of its sides,the seat thereof in a cradle of the building structure, at the same timeas it is associated with positioning means thereof on said threadedportion allowing it to be firmly located at any point along saidthreaded portion to adjust the distance of the panel from the buildingstructure.

A further feature of the invention, directly associated with theforegoing one, lies in the fact that the building structure, in whichthe cement mortar panel with prestressed biaxial reinforcement isinstalled, comprises cross member sections which, horizontally fixedlyattached to uprights at one of their sides, have the opposite end to thefixed one overhanging and forming an upwardly open channeled cradle,which forms a seat for the polygonal plate incorporated in the fixationmembers inserted in the anchoring means of the versatile operatingmeans.

Further features of the invention, which are associated with theforegoing two, consist of the means for positioning the polygonal plateon the threaded portion of the fixation member may be formed byarrangements of the group comprising a threaded sleeve which, beingfixedly attached to the polygonal plate, rotates along said threadedportion of the fixation member or a through hole in the polygonal platefor said threaded portion in cooperation with two nuts, one on each sideof the polygonal plate which rotate along said threaded portion in thesense of positioning and fixing it at a point at a set distance from thebuilding structure.

Yet another feature of the invention is constituted by the fact that thepolygonal plate forming the positioning means is seated at one of itsedges on the lower side of a C-shaped section horizontally installed inthe structure, at the same time as the threaded portion of the fixationmember, which extends from the panel and is attached to said polygonalplate, crosses through the open space formed lengthwise between the twoflanges of the said C-shaped section. In this case, the dimension of theC-shaped section is narrower than the vertical dimension of thepolygonal plate in its seated position therein, while having at itsupper side on the upper flange, opposite to the side on which thepolygonal plate is seated, passage gaps dimensioned for the verticalinsertion of the polygonal plates mounted in the panels. The purpose ofthis is that in the final installed position of the panel the polygonalplates are situated at points of the C-shaped section where there are nopassage gaps.

A further alternative feature of the foregoing lies in the fact that themember for final fixation of the panel in the building structure, whileremaining operable, consists of a screw which, retained in the buildingstructure, may be screwed into a screw thread provided in the deep axialblind hole of the anchoring means of the plug inserted in the panel.

A further feature of the invention, associated with the handlingmembers, consists of the fact that the said handling members formed bythe support rods, at the same time as they are fixed in the axial blindholes of the plug bodies forming the anchoring means, retain a closureplate which with its Teflon-coated active surface engages the flatannular end surfaces of the plug bodies and the mortar surface formingthe hidden face of the panel, encapsulating the mold.

A further feature of the invention is constituted by the fact that eachof the automatic gripping devices consists of a mechanism which is ofthe type driven by means selected from the group formed by electric,pneumatic and hydraulic means and is provided with gripping means whichare complementary to the gripping portion of the handling members. Aplurality of these automatic gripping devices is incorporated in ahorizontal frame which is provided with vertical movement and spacerswhich limit its seating on the mold while they are located in the framein accordance with the positioning contemplated for the insertion of theplugs in the fresh mass of the cement mortar which will form the panel.

A further feature of the invention lies in the fact that the surface ofthe mold on which the cement mortar mass for forming the visible face ofthe panel rests comprises a bottom wall which is formed by aTeflon-coated sheet which may be provided with a defined pattern on itssurface and side walls against which the said mortar mass must beapplied to form the edges of the panel and which are formed byTeflon-coated plates having no defined pattern.

Finally, on the other hand, the invention comprises a process forcorrectly carrying out the manufacture of the panel having prestressedbiaxial reinforcement of the invention, which process, usingsubstantially flat metal molds having a bottom wall and side moldingwalls and a closure cover, consists essentially of the following steps:

a. providing in each of the molds a biaxially stressed reinforcementformed by two series of steel cables or rods, in each of which thecables or rods are mutually coplanar, parallel and equidistant, with theorthogonal superpositioning thereof forming a grid.b. pouring a mass of cement mortar in the mold and leveling itsthickness.c. inserting in spaces of the grid a plurality of plugs, as theversatile operating means which, after the mortar has set, are providedwith panel handling and/or fixation members.d. closing the upper surface of the mold with a mold encapsulatingcover.e. transferring the closed mold to a modular tunnel kiln in which themortar is pre-cured.f. progressively removing the molds from the tunnel kiln and strippingthe pre-cured panel from each of them.g. post-curing the pre-cured panels, andh. quality control and trimming the external branches of thereinforcement elements.

Further features of the process of the invention consist of thefollowing conditions:

i. the pre-curing step in the modular tunnel kiln is effected bymaintaining the mold with the mortar, the reinforcement and theversatile plugs at a temperature of 50° C. for 7 hours.ii. the post-curing step in modular tunnel kiln is effected bymaintaining the pre-cured panel at a temperature of 50° C. and humidityof 95% for 48 hours.iii. The bottom wall, the side walls and the mold closure cover arecoated with a layer of Teflon on their surfaces which contact with thecement mortar mass.

BRIEF DESCRIPTION OF THE DRAWINGS

To facilitate the understanding of the foregoing ideas, there aredescribed hereinbelow some preferred embodiments of the object of theinvention, wherein there are brought together the manufacturing processand the product thereby produced, consisting of a cement mortar panelwith prestressed biaxial reinforcement, with reference to theaccompanying drawings which, in view of their merely illustrativenature, do not affect the scope of the invention. In the drawings:

FIG. 1 is a cross sectional view of a portion of a cement mortar panelwith prestressed biaxial reinforcement, showing one of the versatileoperating means of the invention.

FIG. 2 is a schematic view of the distribution of the versatileoperating means in a cement mortar panel with prestressed biaxialreinforcement relative to said prestressed biaxial reinforcement.

FIG. 3 is partly sectional elevation view of a plug forming oneembodiment of the versatile operating means which, according to theinvention, have been adopted for the handling and attachment of a cementmortar panel with prestressed biaxial reinforcement to a buildingstructure.

FIG. 4 is a side elevation view of an embodiment of a handling memberfor the cement mortar panel with prestressed biaxial reinforcementwhich, in engagement with the versatile operating means, allows thehandling and installation of said mortar panel with prestressed biaxialreinforcement during its manufacture and attachment to the resistantstructure of a building.

FIG. 5 is a partly sectional elevation view of the plug according to theembodiment of the versatile operating means shown in FIG. 3 after it hasbeen occluded in a cement mortar panel with prestressed biaxialreinforcement and the embodiment of the handling member shown in

FIG. 4 has been engaged therewith.

FIG. 6 is a sectional view of an anchoring point of a cement mortarpanel with prestressed biaxial reinforcement in a metal section of aresistant structure of a building.

FIG. 7 is a partly sectional elevation view of an embodiment of a memberfor final fixation of a panel to the building structure which is formedby a polygonal plate and includes positioning means therefor constitutedby two nuts.

FIG. 8 is a partly sectional elevation view of a detail of anotherembodiment of a member for final fixation of a panel to the buildingstructure which is formed by a polygonal plate and includes positioningmeans therefor constituted by a threaded sleeve.

FIG. 9 is a schematic view of a group of members allowing for handlingof the cement mortar panel with prestressed biaxial reinforcement bothin its preparation and molding process and in the removal thereof fromthe mold.

FIG. 10, similarly to the previous figure, shows the group of membersaccompanied by certain details situated in functional parts of some ofthem.

FIG. 11 is a top plan view of the arrangement of the members of FIGS. 10and 11 in an operative frame.

FIG. 12 shows, like the cases of FIGS. 10 and 11, a specific embodimentof an automatic gripping device which allows action to be taken on theversatile operating means in the handling of the cement mortar panelwith prestressed biaxial reinforcement.

FIG. 13 is a partly sectional view of a detail of the assembly of apanel in a C-shaped section of the structure of a building by way offixation means formed by a polygonal plate which is associated with aplug having an open passage for one of the biaxial reinforcementmembers.

FIG. 14 shows, like the previous case, the members included in FIG. 13,with the exception that the plug has an enclosed passage for one of thebiaxial reinforcement members.

FIG. 15 is a perspective view of a detail of a building structure inwhich the horizontal support section for the panels is formed by aC-shaped section having gaps for vertical insertion of the polygonalplates of the fixation means.

FIG. 16 is a top elevation view of a C-shaped section having gaps inwhich; at the left hand side, a panel has been installed while at theright hand side a panel is shown in the process of insertion of thepolygonal plates.

FIG. 17 is a schematic view of the layout of the manufacturing means forthe cement mortar panels of the invention according to their location ina hypothetical industrial plant for their preparation.

DESCRIPTION OF VARIOUS EMBODIMENTS

FIG. 1 shows a small fragment of a panel 1 of cement mortar withprestressed biaxial reinforcement 2 incorporating versatile operatingmeans therefor in a building structure which means are formed, in apreferred embodiment, by a plug 3 which is located in said panel 1 asshown in FIG. 2, where the arrangement thereof in the grid formed by theprestressed biaxial reinforcements 2 is shown.

FIG. 3 shows in detail a preferred embodiment of the versatile operatingmeans of the panel 1 which are formed by said plug 3. This consists of ashort, thick body portion 4 having at one end means 5 for retaining itin the hardened mortar of the panel 1. The means 5 are formed by anoutwardly extending polygonal shoulder of star or other shape and, inthe present case having the form of a flange, while in the rest of thebody portion 4 there are the anchoring means 6 formed by a deep axialblind hole 7, having internal reliefs 8 and which opens out axially andcentrally of a flat annular end surface 9 which limits the correspondingend of the body portion 4 of the plug 3 and lies flush with the hiddenface of the panel 1, without projecting therefrom, as shown in FIG. 1.

With regard to the above mentioned versatile operating means for thepanel 1, the retaining means 5, as shown in FIG. 5, are housed in themortar mass before it hardens and within the grid formed by theprestressed biaxial reinforcements 2, under said reinforcements andwithout reaching the visible face 10 of the panel 1, while the anchoringmeans 6 to a building structure have a portion thereof formed by theflat annular end surface 9 which lies flush with the hidden face 11 ofthe panel 1.

The internal reliefs 8 provided in the deep axial blind hole 7 of theplugs 3 forming the attachment means 6 are of the group comprising screwthreads such as those shown in FIG. 3, bayonet fittings and barbedsurfaces, not shown in the drawings.

As shown in FIGS. 4 and 5, the anchoring means of the plugs 3 arecomplemented by handling members 12 which may be engaged with the deepaxial blind hole 7 thereof and project outwardly in the fixed positionthereof from the surface of the flat annular end surface 9 limiting thecorresponding end of the body portion 4 of the plug 3.

One possible embodiment of the said handling member 12 consists of ananchoring rod 13 which is provided at one end thereof with an anchoringportion 14 which is complementary to the anchoring means 6 of the plug3, and at the other end it comprises a gripping arrangement 15 withwhich an automatic gripping device 16 may engage as shown in FIG. 9.

According to a first stage of use of the versatile operating meansembodied by the plug 3, the handling member 12 may be screwed in thescrew thread 8 of the deep axial blind hole 7 of said plug 3 andconsists of a support rod 13 which, as shown in FIGS. 4 and 5, has atone end a fixation portion 14, which in this case is threaded andcomplementary to the said screw thread 8 of the plug 3 and at the otherend it comprises a gripping arrangement 15, formed by a throat 17 and achamfer 18, with which the automatic gripping device 16 may engage.

In a second, and normally definitive, stage of use of the said versatileoperating means embodied by the plug 3, as shown in FIG. 6, the handlingmember 12 engageable with the deep axial blind hole 7 of a plug 3 isreplaced by a fixation member which is of a type capable of beingscrewed into the screw thread 8 of said plug 3 and consists of a screw19 for fixation of the panel 1 to a section 20 of the buildingstructure. The screw 19 may be accompanied by retaining washers or othersecurity means.

In FIG. 7 there is shown a preferred embodiment of a final fixationmember 21 for the panel 1 to the structure 22 of the building which,while remaining removable, has one end 23 inserted in the deep axialblind hole 7 of the anchoring means 6 of the plug 3 and the other end24, opposite to the former, forming a threaded portion which projectsfrom the hidden face 11 of the panel 1 and passes through a polygonalplate 25 which forms the seat therefor in the building structure 22.

The building structure 22 is formed mainly by transverse sections 26which are fixedly attached horizontally to uprights 27 by one of theiredges 28 f while at their opposite edge they form an upwardly openchannel-shaped cradle 29. Such cradle 29 forms a seat for one edge 30 ofthe polygonal plate 25 which is attached to the final fixation members21 inserted in the anchoring means 6 of the versatile operating meansformed by the plug 3. The polygonal plate 25 is seated by the edge 30 ofone of its sides in the cradle 29, at the same time as it is associatedwith positioning means therefor on said threaded portion of the end 24allowing it to be fixedly located at any point along said threadedportion to adjust the distance from the panel 1 to the buildingstructure 22 and thereby assure that the visible faces 10 of the facadepanels are coplanar.

As shown in FIGS. 7 and 8, the positioning means for the polygonal plate25 on the threaded portion of the end 24 of the final fixation member 21are formed, as shown in FIG. 7, by arrangements of the group comprisingthat of a through hole 31 in the polygonal plate 25 for the passage ofsaid threaded portion of the end 24 in cooperation with two nuts 32 and33, one on each side of the polygonal plate 25 and which are rotatablymoved along said threaded portion of the end 24 in the sense of locatingand fixing the plate in a point at a certain distance from the buildingstructure 22, while in FIG. 8, the said positioning means are formed bya threaded sleeve 34 which is integral with the polygonal plate 25 andis rotatably moved along said threaded portion of the end 24 of thefinal fixation member 21.

In FIG. 9 there is shown the positioning of the automatic grippingdevice 16 relative to: a mobile support frame 35; the handling members12, formed by the support rods 13 after being fixed in the axial blindholes 7 of the body portions 4 of the plugs 3; the panel 1, with theprestressed biaxial reinforcement 2; a Teflon-coated base plate 36 ofthe mold which, having a visible texture appropriate for a facade formsthe visible face 10 of the panel 1, with the mold holder 37; and thefact that it retains together with the said body portions 4 of the plugs3 a closure plate 38 whose contact surface with the said body portions 4of the plugs 3 and with the mortar of the hidden face 11 of the panel 1is Teflon-coated.

As shown in FIG. 10, walls 39 or surfaces of the sides of the moldagainst which the mortar mass for forming the edges of the panel 1 mustbe applied, like the Teflon-coated bottom wall 36 and closure 38 plates,are formed by Teflon-coated plates through which the prestressed biaxialreinforcements pass. The latter are stressed by hydraulic devices 40mounted on the mold holder 37 which, in turn, is located on rotaryrollers 41.

In FIG. 11 there is shown a possible embodiment of support for thehorizontal mobile frame 35 capable of vertical movement and providedwith a plurality of automatic gripping devices 16 which are situated inaccordance with the positioning contemplated for the plugs 3 in thepanel 1. FIG. 12, which is substantially similar to FIGS. 9 and 10,shows that the mobile support frame 35 for the automatic grippingdevices 16 is provided with spacers 41 which limit its seating on themold, at the same time as it shows one possibility of operation of oneembodiment of an automatic gripping device 16 which is provided with anautomatic gripping device 42 driven by the rod 43 of a piston 44 slidingin a fluid-operated cylinder 45. In FIG. 13 there is shown, on the onehand, a panel 1 with its biaxial reinforcements 2 and a plug 3, arrangedrelative to one another in such a way that one of the members 2A of thebiaxial reinforcements 2 extends in a slot 46 provided in the headformed by the retaining means 5 of the plug 3 in the panel 1, while onthe other hand it shows the assembly of a polygonal plate 25 to thefinal fixation member 21 and the seating thereof by its edge 30 in aC-shaped section 47 which is horizontally attached to an upright 27. Thesaid C-shaped section has a base wall 48, a lower side 49 followed by alower flange 50 and an upper side 51 followed by an upper flange 52,there being between the lower flange 50 and the upper flange 52 an openlongitudinal space 53 through which said fixation member 21 extends.

In FIG. 14 there is shown the same members as in FIG. 13, although themember 2A of the biaxial reinforcements 2 extends through a hole 54diametrically formed in the head forming the retaining means 5 of theplug 3 in the panel 1. It will be seen in both figures that a member 2Bof the biaxial reinforcements 2 perpendicular to the member 2A extendsin the vicinity of said head without engaging it. Nevertheless, it iscontemplated that said member 2B also may engage said head, either alonga slot perpendicular to the slot 46 provided for the member 2A, orthrough a hole perpendicular to the hole 54 for the member 2A.

In FIG. 15 there is to be seen an upright 27 and a C-shaped section 47horizontally attached to the upright 27. The C-shaped section 47 haspassage gaps 54 which affect portions adjoining the upper side 51 andthe upper flange 52 and which are dimensioned to allow the verticalinsertion of the polygonal plates 25A and 25D for final fixation of thepanels 1. These polygonal plates 25A and 25B have been shown in thedrawings as independent from the panels to facilitate the understandingof said passage gaps 54.

In the foregoing figure it is to be noted that the polygonal plate 25Ais capable of being inserted vertically in the C-shaped section 47thanks to the passage gap 54 to reach the position shown in phantom lineof the polygonal plate 25C, after which this polygonal plate 25C ismoved to the left of the drawing to reach the position of the polygonalplate 25A. In this position the polygonal plate 25A can no longer movevertically, thereby ensuring the positioning of the panel 1.

In FIG. 16 there is shown the final positioning of a panel 1A, in whichits polygonal plates 25A are blocked in the C-shaped section 47 andspaced from the passage gaps 54, while the panel 1B is being inserted inthe C-shaped section 47, prior to being moved to abut panel 1A.

The manufacturing process of the present cement mortar panel withprestressed biaxial reinforcement is achieved by molding of the cementmortar in metal molds which may be arranged with one of the majordimensions thereof in a vertical position or with the two majordimensions in a horizontal position. The horizontal position ispreferably adopted for the manufacture of flat surfaced panels and thevertical position for the manufacture of panels having a curved,irregular or mixed surface.

The appropriate molds for the said molding operation are made frommetallic materials, especially steel, and are formed by a lower baseplate for making the visible face of the panel, side walls for formingthe panel edges and a closure cover for encapsulating the mold to avoidevaporation of the water from the mortar in the setting stage.

The metal base plate may be smooth and support a sheet of synthetic orother material with an ornamental texture to embellish the visible faceof the panel, or, this metal base plate may be directly provided withthe said ornamental texture. In all cases, it is highly desirable thatthe active surface of the plate is covered with a coating of Teflon.

In turn, the side walls and the closure cover have no type of texture,since the surfaces molded by them are hidden in the building, but it isdesirable that their active surfaces which contact the cement mortar orare facing it are covered with a layer of Teflon.

Complementarily, the molds will be mounted in mold holder frames whichincorporate the prestressing means for the biaxial reinforcement whichwill be hidden in the cement mortar mass of the panel, forming anassembly which is moved for insertion in the tunnels for pre-curing andpost-curing the cement mortar and for stripping the panel from the moldafter the mortar has set.

With the molds as succinctly described above, the steps of the processof the invention for the manufacture of the cement mortar panels withprestressed biaxial reinforcement are as listed below and shown in FIG.17:

a.—placing in each of the molds A a biaxially stressed reinforcementformed by two series of steel cables or rods, in each of which seriesthe cables or rods are coplanar, parallel and equidistant one fromanother, with the orthogonal overlaying of them forming a grid.b.—pouring a mass of cement mortar A1 in the mold and leveling thethickness.c.—inserting in spaces of the grid A2, as versatile operating means, aplurality of plugs which, once the cement mortar has set, are providedeither with handling members or panel fixation members.d.—closing the upper surface of the mold A3 with a mold encapsulatingcover to avoid evaporation of the water from the cement mortar duringthe pre-curing and post-curing steps of the set mortar.e—transferring the closed mold to a modular tunnel kiln B in which thecement mortar is pre-cured.f.—progressively removing the molds from the tunnel kiln B, moldstripping C of the panel pre-cured in each of them and cleaning D of themolds for reuse.g.—post-curing of the pre-cured panels in tunnel kilns E andh.—quality control F and trimming the external portions of theprestressed biaxial reinforcement.i.—drying in store G, surface H, cleaning I and painting J.

The pre-curing step in modular tunnel kiln is effected by holding themold with the cement mortar, the reinforcement and the plugs of theversatile operating means at a temperature of 50° C. for 7 hours, whilethe post-curing step in modular tunnel kiln is effected by holding thepanel stripped from the mold at the end of pre-curing at a temperatureof 50° C. and 95% humidity for 48 hours.

1. A prefabricated cement mortar panel with prestressed biaxialreinforcement, wherein: said panel is formed by a slab of cement mortarwhich has a thickness ranging from 2 to 7 cm and includes a prestressedbiaxial reinforcement, said prestressed biaxial reinforcement beingformed by two series of prestressed cables or rods which are paralleland equidistant within one of said two series, said two series ofprestressed cables or rods crossing each other orthogonally to form agrid, without said cables or rods being attached to one another; saidslab is provided with plugs, said plugs being inserted in at least aportion of one or more spaces in said grid and occluded in the mass ofthe cement mortar slab, without extending from any surfaces of saidslab; a first segment of ach of said plugs forms a retention portion forretaining said plugs in the set mass of the cement mortar; a secondsegment of each of said plugs forms an anchoring portion for temporallyanchoring either a panel handling member for handling said panel or apanel fixing member for fixating said panel to a building structure;said panel is fixedly attached to a building structure by means of aplurality of said panel fixing members, said panel fixing members beinganchored to said anchoring portion of said plugs; each of said panelfixing members has a first end inserted in an axial blind hole of saidplug and a second end, opposite said first end, forming a threadedportion which extends from a face of said panel and passes through apolygonal plate; said polygonal plate is associated with positioningmembers for positioning said polygonal plate along said threaded portionon the second end of said panel fixing member, said positioning membersallowing said polygonal plate to be firmly located at any point alongsaid threaded portion on the second end of said panel fixing member toadjust the distance between said panel and said building structure, saidbuilding structure comprises transverse sections fixedly attached touprights, said transverse sections having a first portion attached tosaid uprights and a second portion in cantilever, said second portionforming an upwardly open channel-shaped cradle; and said polygonal plateseats via one of its edges on said cradle.
 2. The prefabricated cementmortar panel of claim 1, wherein: said anchoring portion of each of saidplugs is formed by an axial blind hole provided with an internalarrangement belonging to the group consisting of: screw threads, bayonetfittings and barbed surfaces; said axial blind hole opens in the centreof a flat annular surface at the end of said plug; and said flat annularsurface is flush with the face of said cement mortar slab.
 3. Theprefabricated cement mortar panel of claim 1, wherein said retentionportion of each of said plugs is formed by a flange that extendsradially outwards from the surface of said plug so as to form an end ofsaid plug.
 4. The prefabricated cement mortar panel of claim 3, wherein.said radially extending flange, which forms said retention portion ofsaid plug, is provided with a passage for at least one of saidprestressed cables or rods, and said passage is formed by an arrangementof at least one of slots and holes.
 5. The prefabricated cement mortarpanel of claim 1, wherein said positioning member, for positioning saidpolygonal plate along said threaded portion on the second end of saidpanel fixing members, is formed by a threaded sleeve integral with saidpolygonal plate, said threaded sleeve threading onto said threadedportion on said second end of said panel fixing member.
 6. Theprefabricated cement mortar panel of claim 1, wherein said positioningmember, for positioning said polygonal plate along said threaded portionon the second end of said panel fixing members (21), is formed by athrough hole in said polygonal plate, said threaded portion on saidsecond end of said panel fixing member passing through said throughhole, and two nuts, one on either side of said polygonal plate, said twonuts threading onto said threaded portion on said second end of saidpanel fixing member.
 7. The prefabricated cement mortar panel of claim1, wherein: said transverse section is formed by a C-shaped sectionhaving a base wall, a lower side followed by a lower flange, and anupper side followed by an upper flange, there being an open longitudinalspace between said lower and upper flanges; said lower side of saidC-shaped section forms said cradle on which said polygonal plate seatsvia said one of its edges; and said threaded portion on the second endof said panel fixing member passes through said open space between thetwo flanges of said C-shaped section.
 8. The prefabricated cement mortarpanel of claim 7, wherein said C-shaped section has a width smaller thanthe vertical dimension of said polygonal plate, when said polygonalplate seats via said one of its edges on said lower side of saidC-shaped section.
 9. The prefabricated cement mortar panel of claim 8,wherein said C-shaped section has on its upper side and on its upperflange at least one passage gap dimensioned for the vertical insertionof said polygonal plate.
 10. The prefabricated cement mortar panel ofclaim 9, wherein, when said said polygonal plate is in its finalposition, seating via said one of its edges on said lower side of saidC-shaped section, said polygonal plate is situated at points of saidC-shaped section where said at least one passage gap is not present.